VistaGen Therapeutics, Inc. (VSTA) and Neuropathic

VistaGen Therapeutics, Inc. (VSTA) and Neuropathic Pain

VistaGen Therapeutics is best known for having developed a versatile stem cell technology platform which can be used to produce superior testing options for new drug candidates, with the potential of saving the drug industry millions or even billions of dollars. But the company also has entered the high-dollar world of neuropathic pain management with the clinical development of AV-101, its small molecule drug candidate for the treatment of pain, and possibly depression and other neurological disorders.

Although the sensation of pain is an important protective mechanism for the body, warning of injuries and disease, it can sometimes persist long after an injury has healed, due to errant nerve impulses. Such chronic neuropathic pain can go on for months, and, in some cases, can itself be detrimental, causing organ damage or leading to a persistent pain state.

The global neuropathic pain market, though competitive, is huge, estimated at $4.8 billion in 2010 and expected by some to grow to $10 billion by 2018, representing an annual growth rate of over 9%. The increasing number of people facing diseases related to neuropathic pain will continue to fuel market growth. Today, the market is dominated by Pfizer’s Lyrica and Eli Lilly’s Cymbalta, with relatively few drugs in total currently approved for the treatment of neuropathic pain.

VistaGen’s AV-101 is a novel, orally available prodrug that is unique in its ability for rapid and efficient transport across the blood-brain barrier, where it converts in form to an effective pain blocker. Specifically, AV-101 is converted in the brain into an active metabolite, 7-chlorokynurenic acid (7-Cl-KYNA), which is an antagonist of the N-methyl-D-aspartate (NMDA) receptors. 7-Cl-KYNA is a synthetic analogue of kynurenic acid, a naturally occurring CNS regulatory compound, and is one of the most potent and selective blockers of the regulatory GlyB-site of the NMDA receptor.

AV-101 is completing Phase 1 clinical development in the U.S., under an active Investigational New Drug (IND) application on file at the U.S. FDA.